Conor McGregor turned down a minimum $10m payday to fight Nate Diaz at UFC 200 through his recent spat with the company, a referee has said.

'Big' John McCarthy, who was due to oversee the rematch bout between the Dubliner and his American counterpart, says UFC CEO Lorenzo Fertitta told him about the "life-changing" amount of cash that was due to switch hands.

Veteran ref McCarthy recalled being at the back of the crowd at UFC 197 on his podcast Let's Get It On MMA, with Sean Wheelock.

He started chatting with the boss and says Lorenzo told him: "I never thought that when I had a guy who was guaranteed $10 million I would have a problem."

"That $10 million might not be $10 million the next time he fights, because it's not UFC 200. And the amount of money they're looking to put into promoting that show and the amount of money they're looking to make off that show is just different to UFC 201.

"Was not coming from Iceland to do that mini tour worth the amount of money that you're actually going to lose?

"It could have been that he made a lot more than that $10m in the UFC fight."